New mothers who survive Covid can pass antibodies onto their babies through their breastmilk for up to 10 months, an American study suggests.
Researchers collected milk donated by 75 women who had recovered from the virus and screened them for the virus-fighting proteins.
They found 88 per cent of them tested positive for an antibody that blocks the virus from causing infection in the respiratory tract.
Further lab tests revealed the majority of Covid-positive milk samples neutralised the virus, suggesting breastfed children gain at least partial protection.
Academics from Mount Sinai Hospital in New York said further work is being done to see if immunity can be passed on via breastmilk after vaccination.
The study was carried out in March, before vaccines were being routinely offered to pregnant American women or females of childbearing age.
It follows a study last week which found pregnant women who have a Covid vaccine pass on their protection to their unborn babies in the womb.
Mothers previously infected with Covid can help protect their babies from the virus for up to 10 months via special antibodies passed through their breastmilk, a study is found. Now researchers are theorizing if these special antibodies could be used to develop new treatments to help protect adults from the virus (stock image)
In the latest study, researchers found mothers produced a Covid antibody, called Immunoglobin A, consistently over time.
They compared milk samples taken from 28 women, one at four to six weeks after Covid infection and the other at four to 10 months after.
The study found women demonstrated ‘significant’ levels of the antibodies over this period.
Immunoglobin A is a special type of antibody found in human secretions, such as breast milk, and primarily offers protection through the linings of the airways and digestive system.
Are Covid vaccines safe for pregnant women and how many have had a jab?
How many pregnant women have had a Covid vaccine?
Data from Public Health England (PHE) shows pregnant women in Britain are still hesitant to receive a jab, with just 10 per cent coming forward for an appointment by the end of July — the most recent date data is available for.
Some 51,724 pregnant women in England had received at least one dose, while 20,648 women had two.
Are there any risks to the mother or baby from taking a jab?
The Royal College of Obstetricians and Gynaecologists recommends that all pregnant women accept the offer of a Covid vaccine.
All major studies show pregnant women are just as safe as the non-pregnant population when it comes to the jab.
And there is no evidence the vaccines have any negative effects on unborn children, with spike in birth defects or stillbirths recorded in inoculated mothers.
Data had been sparse on safety in pregnant women earlier in the year, meaning they were not added to the list of people allowed to have a jab until April in England.
The JCVI decided to wait for data from America to filter through before making a call.
In early April, that data arrived in the form of a major study published by the US Centers for Disease Control and Prevention (CDC). It had tracked the condition of more than 90,000 pregnant women who had received a vaccine, the majority of them in their third trimester.
The CDC was able to report that there were no safety concerns.
Since then, the number of pregnant American women who have had a vaccine has risen to more than 105,000. However, finer data released from within that study set off fresh anxieties.
The CDC closely monitored more than 800 participants. Of that group, 712 had a live birth, while 115 suffered a loss of pregnancy.
This differs from the Immunoglobulin G, a type of antibody found mainly in blood and is triggered by an infection or vaccination.
The researchers also noted that nearly half of the women, 43 per cent, increased the concentration of Covid antibodies in their milk over time.
This finding was unusual because antibodies in the blood are known to wane over time.
Dr Rebecca Powell presented the research findings at the Global Breastfeeding and Lactation Symposium on 21 September.
The Guardian reported that Dr Powell said the breastmilk Covid antibodies may also offer a new way to protect adults from the virus.
‘It could be an incredible therapy, because Secretory IgA is meant to be in these mucosal areas, such as the lining of the respiratory tract, and it survives and functions very well there,’ she said.
‘You could imagine if it was used in a nebuliser-type treatment, it might be very effective during that window where the person has gotten quite sick, but they’re not yet at the point of [being admitted to intensive care].’
Dr Powell’s team is also exploring the relationship between mothers receiving differing Covid vaccines and the level of antibodies produced in breastmilk.
It comes after a study by New York University found pregnant women who have a Covid vaccine pass on their protection to their unborn babies.
Results showed they all had coronavirus-fighting antibodies. Mothers in the second half of their pregnancy had the highest antibody levels in the blood in their umbilical cord, the study found.
Experts said the results weren’t surprising because it happens with other jabs.
But they insisted that findings prove vaccines have the ‘power to protect two lives at once by preventing severe illness in both mothers and babies’.
Dr Ashley Roman, an obstetrician at NYU and one of the lead authors said: ‘If babies could be born with antibodies, it may protect them in the first months of their lives, when they are most vulnerable.’
Children face a tiny risk of falling seriously ill with Covid, a plethora of studies have shown since the pandemic began. But the risk is slightly higher among babies, who have weaker immune systems.
But data from Public Health England (PHE) shows pregnant women in Britain are still hesitant to receive a jab, with just 10 per cent coming forward for an appointment by the end of July — the most recent date data is available for.
This is despite women having been eligible for the vaccine at the same time as the rest of their age group since April.